1. Field of the Invention
The present invention relates to an RFID transponder transmitting/receiving data by radio and an RFID transponder chip included in the RFID transponder.
2. Description of the Related Art
In recent years, an RFID transponder has been drawing attention as a key device for realizing a ubiquitous network. The use of RFID transponders in place of barcodes and the like for product identification eliminates the need to manually read barcodes and the like. The use of RFID transponders remarkably improves product management efficiency. RFID transponders are applicable not only to product identification but also to tracking of the history of products in manufacturing processes (production processes), the history of product management in distribution processes, and the like. Japanese Unexamined Patent Application Publication No. 2003-333950 discloses a method for managing the body temperature of farm animals by attaching RFID transponders to the farm animals. The RFID transponder of this type has an internal temperature sensor for measuring the body temperature of farm animals.
There is a demand for an RFID transponder chip included in an RFID transponder to achieve a sophisticated function, therefore, the integration scale of circuits of the RFID transponder chip is large. However, chip size has been on a decreasing trend in order to realize low-cost chips. Due to the downsizing of chips, temperature sensors mounted on RFID transponders have become more susceptible to heat generated by the operation of circuits in the RFID transponders. This has made it difficult to accurately measure the temperature of a measurement object to which an RFID transponder is attached.